Australia play the "biggest pool match in Rugby World Cup history" when they step out against England at Twickenham on Saturday, knowing a Wallabies victory will consign the Men in White to history as the first host nation to miss the knockout stages of the tournament. So you know England will be primed to hit early, hard and often. Equally Michael Cheika and his players will want to avoid their own week of introspection ahead of their match against undefeated Wales; better to approach that fixture assured of a berth in the knockout and needing to know only who they will play in the quarterfinals. Shannon Parry assesses their campaign to date, and looks forward towards the first of two blockbusters in as many weeks.

Australia opened their campaign with a 28-13 win against Fiji, but still you wonder whether their failure to claim a four-try bonus point will come back to haunt them in the final analysis of Pool A - much as England alone have claimed the maximum return from the Pacific powerhouse. Fiji's ad-lib style of rugby caused headaches for Australia's defence - as it did against England beforehand and Wales afterwards - but the Wallabies showed strength and class at the set-piece, especially at the lineout from which David Pocock, the Man of the Match, scored two tries from unstoppable rolling mauls. Given the trouble that Fiji caused both England and Wales up front, this was a highly encouraging tournament opener even though Fiji stemmed the flow of points in the second half.

Pocock, Michael Hooper and Bernard Foley were key performers, with the 'Pooper' combination in the back-row unbelievable. The work rate of these two players was phenomenal, while their expertise at the breakdown and in defence confirmed their status among the loose forwards in the world; the outstanding effort from these two gentlemen on the night enabled Australia to secure the win, and the Wallabies will be in a strong position if they play as well against England at Twickenham. Foley's kicking performance was also notable, slotting five from six off the tee with his distribution and general kicking on point as he directed the Australians around the paddock.

It was a great start to the campaign, despite being far from their clinical best, with combinations still raw and with plenty of areas to improve. For a first-up clash, I think Australia will have been more than happy with their performance.

Onto Birmingham, for the match against Uruguay, with 14 changes from their line-up against Fiji. Australia crossed for a convincing 11 tries to record the highest winning score of the World Cup to date, and certainly some of the players who have had limited game time over the past few weeks put their best foot forward to crack the A-team. Sean McMahon produced a Man of the Match performance to give Michael Cheika a back-row selection, and the fact he failed to make the bench to play England shows the depth of Australia's flankers; Kurtley Beale was another key performer, and I'm not surprised that he secures a bench spot for the test against England.

Another key positive out of this game was the performance of Australia's tight five. I thought they set a very good platform for the backline to work off, and were dominate in all aspects of the set-piece. The scrum was dominant, the lineout clinical, and the rolling maul was unstoppable with McMahon following Pocock's lead in crossing for two tries. It was positive to see the Australians tightened up their handling in the second half, and showed they can be a more clinical and complete team.

Cheika: Talk is cheap

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But there were some down points, most notably the campaign-ending injuries to Wycliff Palu and Will Skelton. Also the yellow card for Quade Cooper in the first half. I questioned that decision. Was it a high tackle? NO, Was it past the horizontal? NO, Was it a legal tackle? YES. A yellow card for a legal tackle ... I was left a bit more than a little confused. On the whole, however, it was another step forward in the right direction to the Webb Ellis Cup.

It is hard to see, really, where Australia sit in the race for the Web Ellis Cup after these two convincing wins, but it's not hard to see the test against England will be a massive challenge. Australia need to be at their very best as it is do-or-die for England, who will come out firing. Playing on England's home soil with 80,000 plus in the crowd singing 'Swing Low, Sweet Chariot' is sure to be the biggest test for Australia to date.

Australia must step things up to another level, and execute every opportunity they may get. We've been delivered a similar team to that which took to the field against Fiji, as I thought would happen, and Australia will look to control the momentum from the get-go - especially with Hooper and Pocock in tandem at the breakdown.

Wallabies would love to spoil hosts' party

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Momentum is key in a rugby game, as it's so hard to control; it can change easily, but equally it can be very hard to reclaim if you lose it. England vs Wales was a game of momentum swings: England were in control at half-time, leading 19-9, and at 22-12 10 minutes in the second stanza, but the tide turned thereafter and Wales ran out the winners. Momentum is produced by a team creating pressure in attack, and defence creating dominance, but it can turn on the simplest point. We all know that momentum shifts throughout the game, and that's why the team that controls it for the majority of the game will go a long way to winning. Territory, possession and the kicking game will be a vital element in controlling the game this weekend. This match will be provide a true indication as to where Australia are at, and England are playing to keep their World Cup dreams alive; it is sure to be a blockbuster.

Shannon Parry is an Australian Sevens player and captain of the Australian team that competed at the 2014 Women's Rugby World Cup